Table 2.

[4+2] Annulation of phenylacetylene (2a) with monocyclic cyclobutylanilines.

Entry[a]	Substrate	Product	t [h]	Yield[%][b]
1	1b, R = H	3b	12	76
2	1c, R = 4-CF3	3c	24	79
3	1d, R = 4-OMe	3d	18	27
4	1e, R = 2-CN	3e	20	84
5	1f, R = 2-phenyl	3f	20	78
6	1g, R = 2-iPr	3g	24	73
7	1h	3h	12	87
8	1i	3i	14	76
9	1j	3j	18	83

^[a]Reaction condition: substrate (0.2 mmol, 0.1 M in degassed MeOH), 2a (1 mmol), 4a (2 mol%), irradiation with two 18 W LED light bulbs.

^[b]Yield of the isolated product.